1968 – Jan 8, USMC helicopter flies into mountain, fog/light rain, ~Quang Tri, S. Vietnam–all 42

–43 Baugher. US Navy and US Marine Corps BuNos Third Series (150139 to 156169). 4-9-2022.
–42 Gero, David. Military Aviation Disasters: Significant Losses Since 1908. 1999, p. 96.

Narrative Information

Baugher: “
“153710 (MSN 76096) with HMH-463 struck mountain near Quang Tri, SVN Jan 8, 1968 after change from IFY to VFR. 43 killed.”

Gero:
“Date: 8 January 1968 (c.17:00)
“Location: Near Quang Tri, South Vietnam
“Operator: US Marine Corps
“Aircraft type: Sikorsky CH053A (153710)

“The turbine-engine helicopter was on an internal South Vietnamese flight originating at the Marble Mountain Air Facility when it slammed into a mountain and burned 20 miles (30km) south of Dong Ha airfield, where it had last stopped before proceeding on towards its intended destination of Hue.

“All 42 American servicemen aboard (37 passengers and a crew of five) perished. Having apparently lifted off under visual flight rules procedures on what was presumed to have been an instrument flight rules short-range clearance, with directions from the control tower to contact the Dong Ha ground-controlled approach (GCA) radar facility, the rotorcraft proceeded under the control of Dong Ha and later the Hue GCA without such a clearance ever being confirmed or its limits defined.

“Subsequently, 153710 was cleared to the 10 nautical mile fix on the 360-degree radial of the Hue tactical air navigation (TACAN) facility, via the 25 nautical mile fix on the 330-degree radial, and to maintain an altitude of 3,000ft (1,000m). Just before these instructions were given to the helicopter, the Dong Ha GCA controller advised the pilot of a slight drift in its course, but the reception was reported to have been garbled and thus not understood.

“As the helicopter continued to track southward, its targe disappeared from the radarscope due to the ‘shadow effect’ of the surrounding terrain, and around this time radio contact was also lost. Wreckage was located two days later on the 186-degree radial of the Dong Ha TACAN, the CH-53 having crashed approximately at its assigned flight level and about 200ft (60m) below the peak of the mountain.

“At the time of its take-off, the weather at Dong Ha consisted of a low ceiling, with scattered clouds at 300ft (100m) and solid coverage at 1,000ft (300m), and a visibility of 3 miles (5km) in fog and light rain.

“It was ruled that the pilot had erred in judgement in accepting a clearance containing no limit and then proceeding towards the hazardous terrain with both inoperative distance-measuring equipment and poor radio communications. With regard to the primary cause, however, one endorsement of he investigative report noted that the control tower failed to provide a complete clearance even though one had been requested. Considered a factor in the deviation from established operating procedures that contributed to the disaster were the combat environment under which the aircraft and the controlling agencies had been operating. A possible contributing factor was the use of non-standard procedures by the Dong Ha agency due to its lack of communications with the Hue approach control facility. Other factors identified in the report were the instrument meteorological conditions encountered by 153710 and the ‘operationally deficient’ ultra-high-frequency reception characteristics of the earlier model of the CH-53, with a significantly reduced range whenever the aircraft was flying away from the transmitting station. In order to ensure safety, the short-range clearance from Dong Ha began to share with the one used by Quang Tri Marine base, and improvements were also made in the land line communications between air-traffic control agencies in the region.” (Gero, David. Military Aviation Disasters: Significant Losses Since 1908. 1999, p. 96.)

Sources

Baugher, Joseph F. US Navy and US Marine Corps BuNos Third Series (150139 to 156169). Last revised April 9, 2022. Accessed 4-10-2022 at: http://www.joebaugher.com/navy_serials/thirdseries19.html

Gero, David. Military Aviation Disasters: Significant Losses Since 1908. UK and Newbury Park, CA: Patrick Stephens Limited, an imprint of Hayes Publishing, 1999.